The present invention relates to a manufacturing method of superconducting ceramic films, and more particularly relates to an improved method of forming superconducting ceramic films having a relatively increased thickness without superconducting property.
The high-temperature ceramic superconductors discovered in the last couple of years are demonstrating potential for a variety of applications. The ceramic materials of this kind exhibit strong anisotoropy. In the crystalline structure of the ceramics, superconducting current tends to flow along the a-axis and the b-axis, i.e. to flow on the (a b) plane, but the current flow along the c-axis is unlikely. For this reason, it is important to align the c-axes of crystals throughout the ceramic material in the direction in which superconducting current would be desired to pass through in use thereof. The alignment of the crystalline axes is an important technique of the formation of ceramic superconductors.
The alignment of crystalline axes is particularly difficult in case of the formation of thin film. When the thickness of the films is of the order of several micrometers, the formation could be carried out by sputtering, electron beam evaporation, MBE or similar methods. When the thickness, however, is desired to be several hundreds micrometers, e.g. for use in power devices such as power storage devices, the axes inevitably fluctuate to a substantial extent.